#include <random>
#include <iostream>
#include <sstream>
#include <iomanip>
#include <atomic>

int main()
{
    std::random_device rd;
    std::mt19937_64 gernator(rd());
    std::uniform_int_distribution<int> distribution(0, 255);
    std::stringstream ss;
    for (int i = 0; i < 8; i++)
    {
        ss << std::hex << std::setw(2) << std::setfill('0') << distribution(gernator);
        if (i == 3 || i == 5 || i == 7) ss << "-";
    }
    std::atomic<size_t> seq(1);
    size_t num = seq.fetch_add(1);
    for (int i = 7; i >= 0; i--)
    {
        ss << std::hex << std::setw(2) << std::setfill('0') << ((num >> i * 8) &0xff);
        if (i == 6) ss << "-";
    }
    std::cout << ss.str() << std::endl;

    return 0;
}